Process for producing 5-aminopyrazole derivative, and azo dye

A process for producing a 5-aminopyrazole derivative represented by Formula (4) comprising:

• (A) a step of diazotizing an amine compound represented by Formula (1) to prepare a diazonium salt;
• (B) a step of reducing the diazonium salt to prepare a hydrazine compound represented by Formula (2);
• and
• (C) a step of reacting the hydrazine compound with a compound represented by Formula (3) to prepare a 5-aminopyrazole derivative represented by Formula (4),
• wherein the steps (A) to (C) are conducted continuously:
• wherein
• R21 represents an aromatic group or a heterocyclic group, each of which is substituted with a hydroxyl group, carboxyl group or sulfo group,
• R22 represents an electron-withdrawing group, and
• X2 represents a halogen atom, hydroxyl group, amino group, or alkoxy group.

A process for producing an azo dye, comprising:

• a step of producing a 5-aminopyrazole derivative represented by Formula (I), comprising:
• a step of reacting a hydrazine compound represented by Formula (II) with a compound represented by Formula (III) under a condition satisfying Reaction Condition 1 and Reaction Condition 2, wherein
• Reaction Condition 1 is that the reaction is conducted in a reaction solvent containing water, and
• Reaction Condition 2 is that pH of a liquid mixture containing the hydrazine compound represented by Formula (II), the compound represented by Formula (III), the reaction solvent, and an acidifying agent upon charging is within a range of from 2.0 to 4.0 at 25° C.:
• wherein
• R11 represents an aromatic group or a heterocyclic group, each of which is substituted with a hydroxyl group, a carboxyl group, or a sulfo group,
• R12 represents an aliphatic group, aromatic group, or heterocyclic group each of which is substituted or unsubstituted, and
• X1 represents an oxygen atom or NH;
• a step of producing a 5 aminopyrazole derivative represented by Formula (4) comprising:
• (A) a step of diazotizing an amine compound represented by Formula (1) to prepare a diazonium salt,
• (B) a step of reducing the diazonium salt to prepare a hydrazine compound represented by Formula (2), and
• (C) a step of reacting the hydrazine compound with a compound represented by Formula (3) to prepare a 5-aminopyrazole derivative represented by Formula (4),
• wherein the steps (A) to (C) are conducted continuously:
• wherein
• R21 represents an aromatic group or a heterocyclic group, each of which is substituted with a hydroxyl group, carboxyl group or sulfo group,
• R22 represents an electron-withdrawing group, and
• X2 represents a halogen atom, hydroxyl group, amino group, or alkoxy group;
• and
• a step of reacting the 5-aminopyrazole derivative represented by Formula (I) with the 5-aminopyrazole derivative represented by Formula (4).